Spinach and Cheese Strata

I love brunch and my favorite part of brunch is the egg bake.  Not only do they taste good but, they are so easy to whip up and you can do it all the night before.  The entire family loves the egg bake but, we are split on the veggie or no veggie egg bake so, I make both.  I am a fan of eggs, spinach and cheese so, this dish works for me.  I may toss in some mushrooms next time. I had the left overs and it still tasted great reheated.

Spinach and Cheese Strata
Adapted from Gourmet (Epicurious)

Serves 6 to 8

1 (10 ounce) package frozen chopped spinach, thawed, (squeeze of all excess liquid)
1 1/2 cups finely chopped onion (1 large)
3 tablespoons unsalted butter
1 teaspoon salt
1/2 teaspoon black pepper
1/4 teaspoon freshly grated nutmeg
8 cups cubed French bread in 1-inch cubes (1/2 lb)
6 ounces coarsely grated Gruyère (2 cups)
2 ounces finely grated Parmesan (1 cup)
2 3/4 cups milk (do not use non-fat)
9 large eggs
2 tablespoons Dijon mustard

Place in a colander to defrost.  Squeeze handfuls of spinach to remove as much liquid as possible.  

Cook onion in butter in a large heavy skillet over moderate heat, stirring, until soft, 4 to 5 minutes. Add 1/2 teaspoon salt, 1/4 teaspoon pepper, and nutmeg and cook, stirring, 1 minute. Stir in spinach, then remove from heat.

Spread one third of bread cubes in a buttered 3-quart gratin dish or other shallow ceramic baking dish and top evenly with one third of spinach mixture. Sprinkle with one third of each cheese. Repeat layering twice (ending with cheeses).

Whisk together milk, eggs, mustard, and remaining 1/2 teaspoon salt and 1/4 teaspoon pepper in a large bowl and pour evenly over strata. Chill strata, covered with plastic wrap, at least 8 hours (for bread to absorb custard).

Preheat oven to 350°F. Let strata stand at room temperature 30 minutes.

Bake strata, uncovered, in middle of oven until puffed, golden brown, and cooked through, 45 to 55 minutes. Let stand 5 minutes before serving.